Device and method for sharpening blades

ABSTRACT

A blade sharpener includes a blade holder for holding a blade to be sharpened by a rotary wheel having an abrasive surface. The blade holder includes a body having a notch formed in a medial portion of the body for exposing a portion of the blade to the abrasive surface and a support surface for supporting the blade as it travels through the blade holder. The notch comprises a curved back wall for accommodating the rotary wheel.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application No. 60/950,257, filed on Jul. 17, 2007, which is incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The present invention was not developed with the use of any Federal Funds, but was developed independently by the inventor.

BACKGROUND OF THE INVENTION

In the wood working industry a major cost of operation can be the cost of blades. As blades are used they become dull and must be sharpened or replaced. Certain types of blades, particularly those used for planers and jointers, are particularly costly because they cannot be sharpened. These blades have typical dimensions of 12 to 2 inches in length, ⅜ inch wide, and 1/16 inch in thickness. These dimensions are typical and approximate and are not intended to limit the scope of the invention. These blades are commonly known in the industry as Tersa® blades, based on the popular brand of blades manufactured by Samvaz SA, although the invention is not in any way limited to blades exclusively of this brand name or to this type of blade.

Such blades, due to their dimensions, in the past could not be sharpened because they are very thin. Sharpening such blades on traditional sanders would cause the blades to bend, break or otherwise become damaged. These blades typically cost about $250 and replacing them is very expensive.

It is therefore desirable to provide a system and method for sharpening that overcomes these limitations of the prior art and which enables the reusability of such blades.

SUMMARY OF THE INVENTION

The invention comprises a blade sharpener which includes a blade holder for holding a blade to be sharpened by a rotary wheel having an abrasive surface. The blade holder includes a body having a notch formed in a medial portion of the body for exposing a portion of the blade to the abrasive surface and a support surface for supporting the blade as it travels through the blade holder. The notch comprising a curved back wall for accommodating the rotary wheel.

The blade sharpener may comprise a feeder for feeding the blade through the blade holder. The feeder may include one or more spaced feed wheels for feeding the blade through the blade holder.

In one form of the invention the blade sharpener may include a support surface and a lateral support surface for supporting the blade as it travels through the holder. The support surface may be a groove that conforms to the shape of the blade. The lateral support surface may include one or more magnets for holding the blade against the lateral support surface. The support surface may include one or more rollers for facilitating the movement of the blade through the blade holder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an orthogonal view of a device for sharpening a blade in accordance with the present invention.

FIG. 2 is a cross-sectional view of the invention shown in FIG. 1.

FIG. 3 is an orthogonal view of a first preferred embodiment of the invention of FIG. 1 with an automated motorized feeder for feeding a blade through the sharpener.

FIG. 4 is an orthogonal view of a second preferred embodiment of the invention of FIG. 1 comprising a feeder for feeding a blade through the sharpener.

FIG. 5 is a side view of a third preferred embodiment of the invention.

FIG. 6 is an orthogonal view of the invention of FIG. 5.

FIG. 7 is a top view of the invention of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-4, the invention comprises a sharpening device 10 and a method of using the sharpening device. As best seen in FIG. 3, the sharpening device 10 comprises a base 12. A stand 14 is attached to the base 12 for holding a blade holder 16. A motorized feeder 18 may be provided for feeding a blade 20 lengthwise through the sharpener 10 as described in greater detail below. The sharpening device 10 also comprises a grinder 22 mounted to the base 12 for effecting the sharpening of the blade 20.

Referring now to FIGS. 1 and 2, in use the blade 20 is placed within the blade holder 16 of the sharpening device. The blade 20 is guided and supported by a groove 24 formed within the body 25 of the blade holder 16. Preferably, the surfaces of the groove 24 have a shape that is complementary to the shape of the blade 20. Thus, the body 25 of the blade holder 16 provides support along the length of the blade 20 while the blade travels through the blade holder. The body 25 of blade holder 16 may have a top plate 27 for further supporting the blade and defining the groove 24. The top plate 27 is typically attached to the body 25 via fasteners 29.

A notch 26 is formed in the center of the blade holder so that a small portion of the exposed blade can be exposed to an abrasive surface 28, such as a sanding or grinding disk or a diamond plate grinding wheel, being rotated by the grinder 22.

The back wall 31 of the notched center portion 26 of the blade holder 16 is preferably curved at roughly the same arc radius as the sanding/grinding device 22 so that the back wall 31 of the notched area 26 forms a surface against which the sanding device can press the blade while it is being sharpened. This curved back 31 also provides a stop so that the operator cannot press the blade 20 too far causing it to bend or snap.

Once a portion of the blade is sharpened, the blade can be passed through the blade holder 16 lengthwise (along the longitudinal axis of the blade holder 16) so that the next adjacent area of the blade 20 can be sharpened. In this manner substantially the entire length of the blade 20 can be sharpened. The feed direction of the blade 20 through the blade holder 16 is shown by arrow 30 as best seen in FIG. 1.

As best seen in FIGS. 2-4, in one form of the invention the sharpening device 10 includes a motorized feeder 18, having a feed wheel 32 (seen in FIG. 2), for feeding the blade 20 lengthwise through the sharpener 10 as each portion of the blade edge is sharpened. The feeder 18 includes suitable electronics and a switch box to power and control the feeder 18.

In another form of the invention, the blade sharpener 10 is operated manually by the user to feed the blade lengthwise through the sharpening device.

Referring now to FIGS. 5-7, an alternate embodiment of the invention is shown in which like reference numerals are represent similar elements of the invention shown in FIGS. 1-4. The sharpening device 110 comprises a blade holder 116. A motorized feeder 118 may be provided for feeding a blade 120 lengthwise through the sharpener 110. The sharpening device 110 also comprises a grinder 122 for effecting the sharpening of the blade 120.

The blade 120 is guided and supported by a support surface 140 of the blade holder 116. The support surface includes a plurality of rollers 142 for facilitating the movement of the blade 120 through the blade holder 116. Preferably, the surfaces of the groove 24 have a shape that is complementary to the shape of the blade 20. A lateral support surface 144 is also provided for supporting and guiding the blade 120 through the blade holder 116. Rollers 146 are provided for facilitating the movement of the blade 120 through the blade holder 116 in conjunction with rollers 142. Magnets 148 are also provided on the lateral support surface 144 for assuring that the blade 120 is secured against the lateral support surface during the sharpening procedure.

A notch 126 is formed in the center of the blade holder 116 so that a small portion of the exposed blade 120 can be exposed to an abrasive surface 128 of the grinder 122. The back wall 131 of the notched center portion 126 of the blade holder 116 is preferably curved at roughly the same arc radius as the sanding/grinding device 128.

The sharpening device 110 includes a motorized feeder 118 having one or more feed wheels 132 for feeding the blade 20 lengthwise through the sharpener 10 as each portion of the blade edge is sharpened. The feeder 118 includes suitable electronics and a switch box to power and control the feeder 118.

The feeder 118 comprises a drive shaft 150 connected to pulley arrangement for driving the feed wheels 132.

It will be obvious from the above description and the Figures that the invention may be applied to many different types of blades and the invention is not meant to be limited to planer and jointer type blades or blades or to blades of the dimensions described above. Nor is the invention limited to blades for wood cutting, and indeed may also be applied to blades for cutting metal or other materials. The particularly embodiment described herein is provided by way of example and is not meant in any way to limit the scope of the claimed invention. It is understood that the invention is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Without further elaboration, the foregoing will so fully illustrate the invention, that others may by current or future knowledge, readily adapt the same for use under the various conditions of service. 

1. A blade sharpener comprising: a blade holder for holding a blade to be sharpened by a rotary wheel having an abrasive surface, the blade holder comprising a body having a notch formed in a medial portion of the body for exposing a portion of the blade to the abrasive surface and a support surface for supporting the blade as it travels through the blade holder, the notch comprising a curved back wall for accommodating the rotary wheel.
 2. The blade sharpener of claim 1 further comprising a feeder for feeding the blade through the blade holder.
 3. The blade sharpener of claim 2 wherein the feeder comprises at least one feed wheel for feeding the blade through the blade holder.
 4. The blade sharpener of claim 1 wherein the support surface comprises a groove that conforms to the shape of the blade.
 5. The blade sharpener of claim 1 wherein the blade holder comprises a lateral support surface for supporting the blade as it travels through the blade holder.
 6. The blade sharpener of claim 1 wherein the lateral support surface comprises at least one magnet for holding the blade against the lateral support surface.
 7. The blade sharpener of claim 1 wherein the support surface comprises at least one roller for facilitating the movement of the blade through the blade holder.
 8. The blade sharpener of claim 1 wherein the lateral support surface comprises at least one roller for facilitating the movement of the blade through the blade holder.
 9. The blade sharpener of claim 6 wherein the support surface comprises at least one roller for facilitating the movement of the blade through the blade holder.
 10. The blade sharpener of claim 9 wherein the lateral support surface comprises at least one roller for facilitating the movement of the blade through the blade holder.
 11. The blade sharpener of claim 10 further comprising a feeder for feeding the blade through the blade holder.
 12. The blade sharpener of claim 11 further comprising a feeder for feeding the blade through the blade holder. 